Zitat : ccs800 hat am 21 Sep 2004 20:09 geschrieben :

Geräteart : Fernsehgerät Hersteller : Grundig Gerätetyp : St82-774 Messgeräte : Multimeter ______________________ hallo als meine bessere lälfte heute mittag fernseh schaute ging, so sagt sie, plötzlich das bild weg. der ton war aber noch da. bei meinem test von gerade eben zeigte sich nur ein heller wagerechter strich in der bildmitte. der ton ist einwandfrei. ungewöhnliche geräusche sind nicht zu hören. ich habe nun was gelesen von wegen kalten lötstellen am ablenkstecker ... nur habe ich kein schaltbild und somit auch keine ahnung, wo ich suchen / anfangen soll. da der kasten schon einige jahre alt ist lohnt eine reparatur in der fachwerkstatt wohl ehr nicht - oder? also, wer hat nen tipp für mich? grüße michael

Ich habe das gleiche Problem wie ccs800.

DerGeselle/TOM hat schon geantwortet und er besagtes "Vertikal-IC und Sicherheitswiderstand defekt.
Welches Chassis ?". -Auf dem chassi sagt es nur ST82-774, aber ich glaube, dass es CUC7890 gleich ist.

Kann jemand mir die Teilzahlen erklären?
(Bitte, entschuldigung für mein schlechtes Deutsch, ich bin Schwede)

[ Diese Nachricht wurde geändert von: JMG am  2 Nov 2004  1:47 ]

ok JMG !

Take a look at the backside of your TV.
There is a number with CUCxxxx, this is the chassis-number.
And then search here for the manual:

http://wunschkonzert.gmc.to/upload/.....undig

greathings
TOM

_________________
geht nicht, gibt´s nicht !

Ok, thanks for the link to the upload site.

Regarding the CUCxxxx number it is not to be found. I have searched every inch of the rear side and unless I am going blind it only states "ST82-774TOP/EURO". It's an old Grundig 32". According to the cross table references that I have found on the internet it should be CUC7880 and/or CUC7890.

Best regards
Jesper

General info:
For other members on this great forum, which like myself have a TV where it doesn't say the chassi number (CUCxxxx), you can find your chassi number in this cross reference table:
http://cromavideo.webcindario.com/DOCUMENTOS/CHASISGRUNDIG.htm

For owners of a ST82-774TOP/EURO (=CUC7880/90), go to the site below and search for "CUC7880" to download the schematics for free:
http://www.eserviceinfo.com/index.php?what=search2&searchstring=CUC7880
(Maybe Tom has a better link.)
---

Regarding the problem:
I didn't get a chance to bring an oscilloscope from work today but I will do so tomorrow and try to solve the problem. According to the help that Tom gave the problem is due to a bad amplifier within the IC430 (TDA8350Q). Of course, this assuming that the incoming signals to the IC430 are ok and that there are no leaking capacitors or short-cuts. The IC430 is located in the center of the bottom PCB and according to the sample waveform in the schematics the IC430:10 is supposed to output a vertical sync.signal (pulse train).

Once again, thanks for your help Tom! I believe you just saved me a lot of money since I was considering throwing my faulty Grundig away and invest in a plasma instead.

(By the way, if anyone wants to reply please feel free to do so in German (I know... -it's a stupid statement since this is a German forum). I have no problem with understanding written/spoken German, it's only when I have to write/speak for myself that my mind tends to go a bit blank.)

Ok, finally i was prepared with the schematics and an oscilloscope to start troubleshooting but then it turned out that the problem was just due to a glitch or bad contact. The TDA8350Q circuit (Vertikal sync.) was ok.

It's a bit embarrasing but after refurbishing the surface of the connecting pins on the P/S board and the main (bottom) board by scraping them and checking the rest of the power cables the TV was ok again and it has been running for a couple of hours now without any problems.