View previous topic :: View next topic |
Author |
Message |
Bodeslight Guest
|
Posted: Thu Mar 30, 2006 12:21 am Post subject: Grundig CUC2500 doesn't start up |
|
|
Hello,
I have an old Grundig T70 1020A with chassis CUC2500.
The problem is that he sometimes doesn't start up.
After switching on the power I can here a few ticks.
I already replaced the IC655 (TDA 3640), C642 (10uF), C661 (47uF), but that didn't changed anything.
Can someone help me fixing this problem? |
|
Back to top |
|
|
Guest
|
Posted: Sat Apr 01, 2006 7:37 pm Post subject: |
|
|
I don't know this chassis but I had once similar problems with a cuc5511.
Then the problem was a short circuited BU 508A line oscillator.
After replacement the power supply could start up again |
|
Back to top |
|
|
Bodeslight Guest
|
Posted: Wed Apr 05, 2006 3:01 am Post subject: CUC2500 (T70-1020A) start-up problems |
|
|
Anonymous wrote: | I don't know this chassis but I had once similar problems with a cuc5511.
Then the problem was a short circuited BU 508A line oscillator.
After replacement the power supply could start up again |
Thanks a lot for your quick response.
I have searched the CUC5511 drawings, and I couldn't find a BU 508A.
There's a BU 290 (T644) that drive's the line transformer.
Are you sure about the BU 508A? |
|
Back to top |
|
|
BBHE
Joined: 08 Feb 2005 Posts: 12
|
Posted: Thu Apr 13, 2006 8:01 am Post subject: |
|
|
I have had the same problem.
You can check the psu by soldering the bu508D (T521) out. Then connect a normal 220V light bulp between colector - emitter.
If the tv "starts up", the light bulp lights up. You can now check the different output voltage (195V, 12V, 5V etc). Are they ok the defect is somewhere in the line part.
In my case it whas the BU508D that whas defect. |
|
Back to top |
|
|
Bodeslight Guest
|
Posted: Thu May 11, 2006 2:29 am Post subject: |
|
|
I have checked the PSU with a light bulb like you told me but the light bulb doesn't light up. When I measure the BU508D it seems to be OK.
I think that there's something wrong before the transformer.
Can someone give me some new advise?
Thanks a lot. |
|
Back to top |
|
|
Guest
|
Posted: Thu May 11, 2006 5:48 pm Post subject: |
|
|
When it starts, check the health of all powersupplies, and replace the filter capacitors of any that have excessive ripple, then check the rectifier diodes. Check for broken solderjoints especially around larger components. |
|
Back to top |
|
|
|
|
|
You can post new topics in this forum You can reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum
|
eServiceInfo on FB -
Service Manuals Free Download -
Service Diagrams
Free TV Schematics Download -
HARDW.net -
Pinout Master -
Jabse Service Manual Search -
Jabse.InK -
onTap.bg
SnimkiOt.com -
Poblizo.com : пътешествия
Latest Service Manuals :
DCR-TRV410_X SONY • service.zip R8 FOSTEX • FDS6679AZ - P-Channel PowerTrench MOSFET • [pencap radial] TH Series Teapo • UREI-1181 . Various • MAIN B Rolsen • SCHNEIDER • FM AM Stereo-clipper 3312 Nordmende • info Samsung • 4010 SGS •
|