Sansui TU-7700

[Donald Hanson]

Well I hope this is the correct location for this thread and my apologies if not.

I recently won the referenced tuner on eBay knowing in advance that it is weak in the AM band. Now it is due to arrive soon and I am wondering if anyone has some experience with this tuner. It apparently has an AM chip (HA-1151) for which I have found subs as well as nos stuff. I am going forward with that move as well as new caps and any funky looking resistors, diodes etc

Does anyone have a gut feeling that the chip will probably do it or most of it, or am I barking up the wrong tree and should just sit tight until the radio gets here and I have a chance to dissect it?

I did download the service manual so tracing should be at least possible.

Thanks in advance for any insight here.


:confused: :mental:

[Donald Hanson]

Ummm, well I ordered the chip and just received notice that it is backordered (grrr). Think I will try another electronics seller. I am starting to recap the tuner in the meantime. Cool looking tuner, I am so looking forward to hearing it for the first time.

More later if wanted.

dh

[Dave Cawley]

I think you need to fault find it by measurement, not randomly changing components?

Dave

[Donald Hanson]

Well yes, I didn't go into a lot of detail in the earlier posts, but I did in fact locate a bad am chip and some transistors as well. No problem on acquiring the parts. I do a recap on the older audio units as a matter of standard procedure.

If anyone has a service manual for this tuner I would appreciate a copy.

Thank you for your input.

[Mike]

Not quite a service manual, but you can download a schematic from here: http://www.hifiengine.com/manuals/sansui/tu-7700.shtml

[Donald Hanson]

Thank you for that. I got the schematic and am on my way.

I hope to have this operational by early April. That is when I am bringing the boat out of the water and will totally redo several systems, including the onboard audio system. Then in July, it's off for a 6-week trip through the San Juan Islands and up to the North tip of Vancouver Island. So looking forward to that trip.