1. Home
  2. Electronics Down Under
  3. Sanyo CPP2930 TV, chassis A8-A29

Sanyo CPP2930 TV, chassis A8-A29

I'm working on an intermittent fault in a Sanyo CPP2930 TV, chassis A8-A29. The customer describes a vertical collapse (horizontal line) followed by a shutdown and restart. After this happens, the volume is at minimum.

This article ...

formatting link

... talks about a service bulletin "dated 27-4-94 (no. 24) for the CPP2930 and 2530 models, the fault being: 'The TV set switches off and on (CPU resets momentarily) on VCR search mode'."

The author states that "It was then just a matter of purchasing a kit of parts and fitting them on the SYNC and RESET PC board (VE2689)".

I have the details of this rework (3 resistors, 1 capacitor) but am not certain that it will address the aforementioned problem. Is there anything else to check? A tap test has turned up no dry joints or bad connections.

- Franc Zabkar

--
Please remove one 'i' from my address when replying by email.
Reply to
Franc Zabkar
Loading thread data ...

Vertical collapse? I would suspect vertical IC or surrounding circuitry. Try resoldering the IC first and check caps around it.

As for service bulletin -- I beleive it was due to the sync pulses being wrongly detected byth TV when VCR does FF or FREW. Should not happen on normal channel viewing.

Rudolf

Reply to
Rudolf

On Wed, 7 Mar 2007 15:34:39 +1100, "Rudolf" put finger to keyboard and composed:

That's the first place I checked. I tried tapping and freezing but was unable to produce a collapse. I did observe an initial warm up problem where the height was reduced to about 2/3, and I traced the fault to a dry electro, but I'm not convinced that the total collapse is caused by the same component.

Hopefully it is that simple, but I hate to fix something before I witness the fault.

The SC article suggests that a particular VHS tape was able to consistently reproduce the fault. I suppose this could have been due to dropouts, but the author suggested that it may have been due to some Macrovision incompatibility.

One thing which is confusing me is that the "Reset and Sync" board, which is the subject of the bulletin, appears to have two v/sync sources, a TDA2579B and an LA7210. I guess the first is for TV, the latter for VCR. I don't have a circuit diagram, BTW.

- Franc Zabkar

--
Please remove one 'i' from my address when replying by email.
Reply to
Franc Zabkar

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.