Hello stego,I'm not dead but my power supply don't work!
Sorry for my big big delay: problems with my connection

I've replaced all diode,all resistor and now i have a +33v but I haven't the -150v and -7v.

-150v now is -0,00
+150v now is +185v
-7v now is -79v
+12v now is +14v
+9v now is +15v

What's happening?
I will to buy another Grundig 2x8 with defect to heads but electronic functionally.I will replace the power board defect with a functionally power board.
I looked your datasheet ,i've replaced all but there are problems.

Can you to send me the circuit display ,please?
Thank you very much!

[ Diese Nachricht wurde geändert von: Nicola am 14 Feb 2009 11:24 ]

Hello Nicola,

that seems very, very strange!
If you don´t have the negative -150 Volts, why are there -79 Volts at pin 23, where only -7 Volts should be?

Please take a look into "powerboard_2.pdf". The -7 Volts (on pin 23) are taken from the -150 Volts (on pin 21). So, if there are no negative -150 Volts present, no voltage can be present on the -7 Volt string!

Please check for bad soldering points, for oxydation on the pins, and also check the following parts:
R494 (a SKS-2 fuse-resistor with 1 k-Ohm), also R 496 (47 kOhm) and R 495 (1 MegOhm).

Perhaps the pins have oxydation or cold soldering points (on the powerboard or on the main board), and the -150 Volts are really present.

The 12 Volts must be alligned after reparing the powerboard.
When the powerboard is re-fitted into the machine, you can see a variable-resistor (trim-R) on the front upper side of the powerboard (very often fixed with red colour) on position R 462 (also marked as "+D". You must allign the 12 Volts on pin 1 or 2 of the powerboard (also on the lower side of the main board) to exactly 12,5 V (+/- 0,05 V => 12,45 to 12,55 Volts).

The missing voltage of -150 V can make the other voltages getting to high.


If you don´t want to repair the powerboard and try to get one, there is nearly just one way: eBay.
And then it´s great luck to get a machine in good condition.

Best regards
stego

p.s.: What do you mean with "circuit display"?
Is that the front panel with the display unit?
This may have nothing to do with the missing -150 Volts...

_________________

Hello Stego and Nicola,

your conversation is really very helpful for me, too.
I have a 2 Grundig 2280 too, one is more or less working, there are
only some difficulties with the cassette carrier for eject and final position.
The second one doesn´t work. Display and power supply is ok, but no reaction anymore.

May be we can talk later on in another new topic about my still open questions, because you have a big knowledge and I´m a beginner but a big fan from Grundig Video 2000 - the best video system ever developed.


Kind regards from Stefan

Franken, Bavaria

Hello Stego!!
I am still alive!
Sorry for my big delay but I was without computer for a month because I changed house and I have not had time to connect to internet

I repaired the power adapter,finally but it was useless: the VCR does not work, it fails the ablaufsteuerung: You were right in your first post!

I bought a Grundig 2280A for my mistake:The seller told me Grundig 2x8 and did not know whether in 2280 or 2280A because the sticker is missing.

And now I have a problem with the 2280A, I hope you can help me.
(I am unlucky with this model Grundig )

The machine turns on, there's the "click", it seems the time and written CASS,I insert the cassette, all right ,but when the cassette is inserted NO appear included in the display shows "c4 bands etc etc" but still the time and written CASS.If I press the buttons (play, FFWD, Rew, etc. etc.) display their symbols but the vcr no working: the tape does not go on the drum head.If press CASS the tape comes out.

I measured the voltages on the power board.Please,Can you tell me if they are good or is there some problem?

+150 VD ----+162,9
- 150 VD ---- -154,2
+5 VE --- + 4,9
+5 VF --- 0,00
+12VW --- 0,00
+12 VF --- 0,00
+12 VE --- +12,1
+12VD --- +12,2
+33V --- +32,1
+12VDM--- +12,2
+18v --- +18,0
-7 VD --- -6.6

When I insert the cassette and simulates the play (of course nothing happens but the symbol appears on the display)voltages +5 VF becomes from 0.00 to 4.9 while the VW is +12 from 0.00 to +11.7.

Do you think a ablaufsteuerung problem?
how can I fix this?
Sorry again for the long silence,Stego.I hope in your help.
Best regards from Florence!
Thanks

Nicola


[ Diese Nachricht wurde geändert von: Nicola am 11 Mär 2009 20:04 ]

Hello Nicola!

Nice to hear again from you!

Now to your "new" 2x8 2280a:

All voltages from the power supply seem ok, perhaps a little bit too low.

V_D = in german "Volt Dauerspannung" = permanent voltage
V_E = in german "Volt Eingang" = input voltage
V_W = in german "Volt Wiedergabe" = voltage in play mode
V_A = in german "Volt Aufnahme" = voltage in record mode
V_F = in german "Volt Funktion" = operation voltage.

The 12 V_D-voltage should be 12,5 V +/- 0,05 V, measured in play mode.
You can allign this with the trim potentiometer on the top side of the power module (inserted in the machine!). If you look from the front of the VCR on the power module, there is a metal cover above it, and on the right side in front there is a trim potentiometer.
Turn it so wide, so that the 12 V_D voltage is as near as 12,5 volts as possible.

But that´s not the reason for the fault.

Now to the fault with the cassette drive:

Please check all the plugs on the "Ablaufsteuerung" for damages or breaks in the plastic plug (most of them coloured red and black).

Also check FA2 (downside the cassette drive).
In this thread:
https://forum.electronicwerkstatt.d......html
I have posted a few pages from the mechanical part of the service manual. On "Seite_1.pdf" you can see the switch FA2.
This switch must be closed when the cassette holder is upside (Eject position) and must open it´s contacts when the cassette holder turns downside.

And also check the cassette load switch (CL) in the "cassette lip" in front of the cassette holder. This switch must be closed all the time a cassette is inside the cassette holder.

If you press any button (Play/FF/REW) and wait a few seconds, is there a blinking "F" in the display (left side beside the clock)?

If yes: please press the cassette load switch manually, so that the cassette holder goes down.
Now look, if the winding motors on the left and right side begin to turn (left motor: anticlockwise direction, right motor: clockwise direction).

So long.
After you have checked this things, we will go on again.

Best regards
stego




_________________

Hello Stego,thank you very much for help me.
My english is very bad,sorry.
I have made the tests you said to me:

I looked into Seite 1 and FA2 is perfect
Also i looked into Seite 2 the number 1 "Cassetteladenkontakt" is OK!
Cassette load (CL) in the "cassette lip"is ok!

cassette drive is perfect.
When i insert cassette,it goes down into cassette drive but on the display NO appears "C4 ecc ecc BAND" but time and "cass" also if is present a cassette into downside!.
If i press the cassetteladenkontakt with my finger,it goes down perfectly.
Don't working the winding motor and no working functions play,rew,ff .Only working "Cass" : if i press this, the cassette eject.

Please look at this video:
http://www.youtube.com/watch?v=1y2iECO-5l8

But i want to tell you all about this problem.
When i received this Grundig, it was perfect.Only problem: the belt was old.I opened the bottom down,i changed the belt and I turned on the grundig whitout lid down.The vcr was in a wood chair and in this moment the time of display was blinking and the winding motors goes without to stop.I disconnected the ablaufsteuerung (first cable left with many colour) and when i disconnected i looked a little smoke.
What is happened?
Best regards stego and thank you very very much!!
Nicola



[ Diese Nachricht wurde geändert von: Nicola am 12 Mär 2009 18:57 ]

[ Diese Nachricht wurde geändert von: Nicola am 12 Mär 2009 18:58 ]

[ Diese Nachricht wurde geändert von: Nicola am 12 Mär 2009 19:22 ]

[ Diese Nachricht wurde geändert von: Nicola am 12 Mär 2009 19:25 ]

stego,please: look at the photo.

Keine Links zu Werbeschleudern - Um die Grafik passend zu verkleinern > paint verwenden! - photobucket.com

Is it normal that where I written the yellow crosses ,there are 0.00 v?
all cables from first ablaufsteureng cable (with many colours)are without voltage!

There isn't "F" when I press play,rew,ff ext..
There is "F", sometimes, when i press the cassette lip with my finger but there isn't when i insert the cassette..

thanks
Nicola

[ Diese Nachricht wurde geändert von: Nicola am 12 Mär 2009 19:35 ]

[ Diese Nachricht wurde geändert von: Nicola am 12 Mär 2009 19:36 ]

Hello Nicola,

thanks for the photos and the video.

Now to your yellow crosses in the photo:

In the middle of the photo you can see the small printed board mounted on the magnet for the reel-breaks.
Of course, there is no voltage in stop mode. At inserting a cassette, the magnet must start (you must hear a clear and loud "Click"). This click must be present also after turning on the VCR.

I can´t tell you off-hand, if the "Ablaufsteuerung" of the 2280a is the same as of the 2280 (without a).

It may be, that you have damaged the fuse-resistor at de-connecting and re-connecting the plug with the multi-colour cables (marked as "L7" - please take a look into "Ablaufsteuerung_3.pdf"). The fuse resistor has 1 Ohms and is located at position R1630.
If this R1630 is dead, the winding motors don´t get their voltages, the machine cannot read in the time of the cassette, because no reels turn. And as a reason to this, the machine also cannot thread in the tape!

In your video it looks a bit strange to me, that in the clock display the double points between the hour and the minute display don´t blink, but light permanent.
Does the clock run? Or does ist stay on the same time? Can you allign the time and date (buttons below the cover)?
Is the accu on the "Ablaufsteuerung" ok?

And of course, check R1630.

So long for the moment!

Best regards
stego

_________________

Zitat : stego hat am 13 Mär 2009 10:16 geschrieben :

Hello Nicola, thanks for the photos and the video.

Hello stego,thanks to you for helping me!

Zitat :

Now to your yellow crosses in the photo: In the middle of the photo you can see the small printed board mounted on the magnet for the reel-breaks. Of course, there is no voltage in stop mode. At inserting a cassette, the magnet must start (you must hear a clear and loud "Click"). This click must be present also after turning on the VCR.

Exactly,stego.When the machine is stopped, there isn't voltage but if I insert a cassette,there is v 11,8 in the black cable and v 8,7 in the browne cable.There is also the "click" when i insert cassette and when I turn on/turn off the machine
Please look at the photo:

Keine Links zu Werbeschleudern - Um die Grafik passend zu verkleinern > paint verwenden! - photobucket.com

Zitat :

I can´t tell you off-hand, if the "Ablaufsteuerung" of the 2280a is the same as of the 2280 (without a).

what is "off-hand"?
The "Ablaufsteuerung" of the 2280a isn't the same as the one of 2280,but very similar:
(Photo):
Keine Links zu Werbeschleudern - Um die Grafik passend zu verkleinern > paint verwenden! - photobucket.com

Zitat :

It may be, that you have damaged the fuse-resistor at de-connecting and re-connecting the plug with the multi-colour cables (marked as "L7" - please take a look into "Ablaufsteuerung_3.pdf"). The fuse resistor has 1 Ohms and is located at position R1630. If this R1630 is dead, the winding motors don´t get their voltages, the machine cannot read in the time of the cassette, because no reels turn. And as a reason to this, the machine also cannot thread in the tape!

In the Ablaufsteuerung 2080a there isn't a fuse resistor r1630 but there are 3 fuse resistors.One of the them is R1536,the other 2 i called R?1 and R?2 because their true names are hidden by the fuse resistor themselve and i haven't the service manual of the 2280a
Please look at the photos:
Keine Links zu Werbeschleudern - Um die Grafik passend zu verkleinern > paint verwenden! - photobucket.com
Keine Links zu Werbeschleudern - Um die Grafik passend zu verkleinern > paint verwenden! - photobucket.com
Keine Links zu Werbeschleudern - Um die Grafik passend zu verkleinern > paint verwenden! - photobucket.com

which fuse resistors can be responsable of no-voltage for L7?
I tested all with my multimeter (ohm 20-200k) and all of them are 0,00 in the display.

Zitat :

In your video it looks a bit strange to me, that in the clock display the double points between the hour and the minute display don´t blink, but light permanent. Does the clock run? Or does ist stay on the same time? Can you allign the time and date (buttons below the cover)? Is the accu on the "Ablaufsteuerung" ok?

The clock run also if the double points are not blinking.I can allinig the time and the date by buttons into the cover.The buttons working perfectly.The accu isn't ok: the board is damage near the accu.
Photo: Keine Links zu Werbeschleudern - Um die Grafik passend zu verkleinern > paint verwenden! - photobucket.com

Please,tell me which test i can do..
Thank you very much
Best Regards
Nicola

[ Diese Nachricht wurde geändert von: Nicola am 13 Mär 2009 21:24 ]

[ Diese Nachricht wurde geändert von: Nicola am 13 Mär 2009 21:26 ]

Zitat :

It may be, that you have damaged the fuse-resistor at de-connecting and re-connecting the plug with the multi-colour cables (marked as "L7" - please take a look into "Ablaufsteuerung_3.pdf")

Hello stego,i'd like remember: the problem is borned before my disconnecting-reconnecting the multicable in the L7.

"I opened the bottom down,i changed the belt and I turned on the grundig whitout lid down.The vcr was in a wood chair and in this moment the time of display was blinking and the winding motors goes without to stop.I disconnected the ablaufsteuerung (first cable left with many colour) and when i disconnected i looked a little smoke. "

another photos Ablaufsteuerung 2080 and 2080A
Keine Links zu Werbeschleudern - Um die Grafik passend zu verkleinern > paint verwenden! - photobucket.com
Keine Links zu Werbeschleudern - Um die Grafik passend zu verkleinern > paint verwenden! - photobucket.com

thanks stego!!!

Hello Nicola,

with "off-hand" I mean, I can´t tell you from my mind.

On one of the photos I can see, that the CMOS-RAM IC (PCD8571, position IC1525) is damaged by the electrolyte from the accu. This can be the faulty part. Of course, the accu itself can cause failures in the "Ablaufsteuerung", so if this is defective, it should be replaced with a new one, or at least it should be taken out. A defective accu can cause a short circuit and as a reason to this a faulty operation of the module.

Perhaps some more IC´s are dead as a reason to this.

It may be very difficult to repair this machine again....


the Voltages on the magnet are ok. 11,7 Volts, this is the voltage when the magnet starts, and as the contact behind the magnet opens, there are only 11,7 Volt minus 8,9 Volts = about 3 Volts for holding the magnet present. That´s all right.

The three resistors (where you mean that may be fuse resistors) are most of all NO fuse resistors, but only normal resistors.

I will look into my service manual, if there is the also the part for the "Ablaufsteuerung" for the Video 2280a. There are indeed a few differences between 2280 (without a) and 2280a.

You can check the reel motors for function: Disconnect machine from mains, disconnect R7 again and put a DC voltage of about 3 - 12 Volts to each of the two motors. The break rubbers (wich are on the magnet) must be taken away by hand. The same procedure can be made with the capstan motor and the video-head-motor. Always disconnect the plug of the motor before testing from the modules!

You wrote:

Zitat :

I turned on the grundig whitout lid down

What ”lid" do you mean here?

You hear again from me. I will search for my service manual first.

Best regards,
stego


_________________

Hi stego,thanks for you reply!

Accu is damaged but the machine was working also if accu damaged!
The machine stop working for my mistake (i told you this).
I have a new accu varta from another ablaufsteuerung,can i remove from this and to put in the 2280a?

Today important new:
please look at the video:

Keine Links zu Werbeschleudern - Um die Grafik passend zu verkleinern > paint verwenden! - photobucket.com

I will to repair that? I hope..!
Please,if you can,another help!
Thanks Best regards!!


[ Diese Nachricht wurde geändert von: Nicola am 15 Mär 2009 15:42 ]

Zitat :

You wrote: Zitat : I turned on the grundig whitout lid down What ”lid" do you mean here?

lid:

Keine Links zu Werbeschleudern - Um die Grafik passend zu verkleinern > paint verwenden! - photobucket.com

i damaged something in the down machine because i put the machine on the chair without the lid down..
this is the reason for damage.Before that,the VCR was perfect! (except display with time no blinking)