Marantz SR-68U and the BVITMP87PM78F chip

[jeffbiss]

Hello all!

I have a Marantz SR-68U tuner that fails to fully power up, I switched it on and nothing. I opened it up and found that the sub-transformer, T901, is supplying the voltages indicated on page 12 of its Service Manual (4822 725 51193/1999.04/266W855010 AO). However, I find that Power On/Off line is low thus keeping mains power from the input of the main transformer, T902.

I find that the BVITMP87PM78F controller chip is also used in the TEAC AG-H300mkIII but find no information about this chip to help troubleshooting it. I'm assuming that it is looking at the +6VDC line coming from the 7806 regulator, but as that is 5.98VDC, well within the specified output of 5.75 - 6.25VDC, I would guess that either the controller chip is bad or that it is also looking at something else that makes it think that something's wrong.

Does anyone have any troubleshooting information about this controller chip for either the Marantz or TEAC?

Is there any information about this chip?

Thanks in advance, Jeff

 

[Punker X]

SR indicates a receiver. In this forum we primarily deal with tuner (radio) issues. Sort of take from the description that it the entire unit that won't power on, not just the tuner. You will get wider exposer in the solid state or Marantz forum. Thread can be moved if, this more than a tuner issue.

 

[jeffbiss]

Thanks Mike. I'm not big into stereo and so get kind of sloppy as to what I call things. I didn't notice the Marantz forum, I didn't scroll low enough. I'm looking into moving this thread.