Dead FT-736R

[WB8PFZ]

I just purchased a 736R that is dead. It is loaded with band modules that could be installed in another radio. I originally thought the power supply was the problem. The supply needs to be rebuilt, but that is not the only problem. With a 13 volt supply powering the radio the meter lights come on and the ON air light comes on. That's it no display, nothing. I am going to get the service manual but meanwhile was wondering if anyone has any ideas? Thanks Mike

[N4ATS]

The service manual is free all over the place , just Google it , however the 736R is a disaster to work on , sell it for parts , get one working. I repaired them for many years and as you will find the time and energy to rebuild , unless you have tons of time , is not a good idea.

[W9GB]

I just purchased a Yaesu FT-736R VHF/UHF transceiver, that is dead.

Mike -

Contact John, N6AX and see if he has time to assist with your FT-736R restoration/repairs.
John formerly worked in Yaesu USA service, when these were in production (knows the model).

A couple of years ago he restored a used FT-736R that looked new -- but the UHF receiver was deaf and the SK had placed the radio in a box and never sent back to Yaesu for repairs many years ago! Thanks to John -- works again.
http://www.ham-radio.com/n6ax/webdocs/

Fox Tango International
http://www.foxtango.org/phpBB2/viewt...a705a2d4f890d1

FT-736R Power Supply Repair
http://oz1db.dk/start_eng.html

PDF
http://rx.kiev.ua/index.php/servmansoft/yaesu/71-yaesu-ft-736r-ps-repair/download

HRO refers clients to Charles Turner for FT-736R repairs
http://www.eham.net/reviews/detail/1705

w9gb

[KB2CPW]

 Probably a voltage regulator, check all of the voltages as per the service manual.. Richy

[WB8PFZ]

I have checked the  8 volt regulator and it looks good. I need to get the tech manual to continue. I really hate to get rid of hoping it's something easy to find and fix. My hopes are up. Thanks Mike

[WB8PFZ]

So far all the voltages on the main control board look OK. 6 meters is open so going to play there.

[K1ZJH]

Keying voltage getting back on the PTT can roach the uP in that radio. There are a lot of horror stories about 736 rigs that exhibit similar symptoms.

http://groups.yahoo.com/group/FT-736R/message/476

Of course, the first thing to check is the MOX switch on the front panel

Pete

[WB8PFZ]

Is there any chance some one has a setup to check the boards on these. Mike

[W9GB]

Is there any chance some one has a setup to check the boards on these.

Very unlikely.  The only former Yaesu technicians that MAY have such a setup, are the 2 in California (where Yaesu USA service located), previously mentioned in earlier answer.

w9gb

[W9GB]

The Yaesu FT-736R used the Hitachi HD63A01Y0 microprocessor (Q08) on the radio's control board.
This microprocessor is based on the Motorola 6800 family of processors.
http://en.wikipedia.org/wiki/Motorola_6800

HD63A01Y0 : Hitachi Semiconductor, CMOS microcomputer : Hitachi 630x, 1.5 MHz : Masked ROM :
Improved 6800 Microcontroller with on-chip RAM, ROM and peripherals : 16K ROM, 256 RAM

HD63A01Y0 Datasheet IC On-line (China)
http://www.ic-on-line.cn/download.php?id=1100215&pdfid=222F732D44D038E12FAF5AC47FCE1F03&file=0052\hd6301y0cp_397300.pdf

IF you can get the ROM image, then it can be masked on a new processor OR
disassembled to reduce the "re-engineering" required for a replacement project.

China IC mart suppliers note that they have stock -- some DIP64, others QFP package..
http://www.chinaicmart.com/series-HD6/HD63A01Y0.html

The Motorola 6800 processor family was the basis for many follow-on processors in 1970s and early 1980s.
The original Apple I could run with a 6800 or 6502 processor.  
Apple II computer used the 6502, and the Radio Shack Color Computer used 6809 processor.
==
DASMx - DASMx is a disassembler for a range of common microprocessors, including the Motorola 6800 family and single chip variants (including Hitachi 630X devices).
http://myweb.tiscali.co.uk/pclare/DASMx/

The disassembler takes as input a binary code/data image file (typically a ROM image) and generates either an assembler source file or a listing file. DASMx is a multi-pass disassembler with automatic symbol generation. DASMx can optionally use a symbol file containing user-defined symbols and specifications of data areas within the source image.
DASMx includes a powerful feature called code threading. Using known code entry points (e.g. reset and interrupt vectors) and by performing partial emulation of the processor, the disassembler is able to follow known code paths within a source binary image.

Use of code threading, together with the multi-pass operation and symbol table management permits readable assembly code output from source images that contain large amounts of data (which tend to confuse most disassemblers).

[W9GB]

I see that you gave up, and are parting out this FT-736R transceiver on eBay.