HELP no display on a FT757 I have just bought - UK Vintage Radio Repair and Restoration Discussion Forum

Gulf1SCY · 30th Aug 2017, 3:58 pm

My new FT757 has no display when powered up it powers up OK and there is reception it does everything changes bands etc but the VFO knob when turned doesn't change frequency.
It would seem the two problems are related no frquency change and no display.
Any help advice would be good
Thanks
Fred G1SCY

Nuvistor · 30th Aug 2017, 7:03 pm

From the user manual,
Page 22 describes the lock button, it can lock everything or various buttons
Page 38 gives more details of the lock function.
Page 92 describes the display. It can be off or various levels of brightness.

Apologies if you have tried these.

Frank
Edit I have just noticed the above info is for the 857, hopefully the 757 has similar functions

Terry_VK5TM · 31st Aug 2017, 4:02 am

This is just a quick reply, but 3 possible causes (I need to dig in to my notes to find the exact details when I get back home).

Dud transistor on the display board (I think), it generates an 8V? line.

Dead display driver (no longer available, but there is an aftermarket kit to replace it if it is still available).

Faulty CPU - no longer available except from another s/hand rig.

Terry

Gulf1SCY · 31st Aug 2017, 9:15 am

Thanks any help is useful. No I haven't tried anything.

Fred G1SCY

Hermit6345 · 31st Aug 2017, 1:22 pm

Have you tried a reset procedure? With the LINEAR button on the back of the radio depressed, depress and release the MARKER button. This should reset the CPU. Worth doing if already not done and may solve your problem.

Gulf1SCY · 31st Aug 2017, 3:30 pm

Nope that didn't work.
I think I'll try and source a display driver as a start.

Terry_VK5TM · 1st Sep 2017, 3:56 am

Ok, had a dig through my notes.

The possible dud transistor on the display board is Q01 (2SC496y).
It generates (or is supposed to generate -8v (minus 8V).

A replacement for the display driver was available from Rudi, DB6RK. Not sure if he still has them, I got mine a couple of years ago.
His email address is on QRZ.

Terry

30th Aug 2017, 3:58 pm	#1
Gulf1SCY Retired Dormant Member Join Date: Aug 2017 Location: Cornwall, UK. Posts: 3	HELP no display on a FT757 I have just bought My new FT757 has no display when powered up it powers up OK and there is reception it does everything changes bands etc but the VFO knob when turned doesn't change frequency. It would seem the two problems are related no frquency change and no display. Any help advice would be good Thanks Fred G1SCY

30th Aug 2017, 7:03 pm	#2
Nuvistor Dekatron Join Date: Aug 2013 Location: Wigan, Greater Manchester, UK. Posts: 9,433	Re: HELP no display on a FT757 I have just bought From the user manual, Page 22 describes the lock button, it can lock everything or various buttons Page 38 gives more details of the lock function. Page 92 describes the display. It can be off or various levels of brightness. Apologies if you have tried these. Frank Edit I have just noticed the above info is for the 857, hopefully the 757 has similar functions Last edited by Nuvistor; 30th Aug 2017 at 7:21 pm.

31st Aug 2017, 4:02 am	#3
Terry_VK5TM Nonode Join Date: Oct 2010 Location: Tintinara, South Australia, Australia Posts: 2,340	Re: HELP no display on a FT757 I have just bought This is just a quick reply, but 3 possible causes (I need to dig in to my notes to find the exact details when I get back home). Dud transistor on the display board (I think), it generates an 8V? line. Dead display driver (no longer available, but there is an aftermarket kit to replace it if it is still available). Faulty CPU - no longer available except from another s/hand rig. Terry

31st Aug 2017, 9:15 am	#4
Gulf1SCY Retired Dormant Member Join Date: Aug 2017 Location: Cornwall, UK. Posts: 3	Re: HELP no display on a FT757 I have just bought Thanks any help is useful. No I haven't tried anything. Fred G1SCY

31st Aug 2017, 1:22 pm	#5
Hermit6345 Rest in Peace Join Date: Oct 2006 Location: North Wiltshire, UK. Posts: 638	Re: HELP no display on a FT757 I have just bought Have you tried a reset procedure? With the LINEAR button on the back of the radio depressed, depress and release the MARKER button. This should reset the CPU. Worth doing if already not done and may solve your problem.

31st Aug 2017, 3:30 pm	#6
Gulf1SCY Retired Dormant Member Join Date: Aug 2017 Location: Cornwall, UK. Posts: 3	Re: HELP no display on a FT757 I have just bought Nope that didn't work. I think I'll try and source a display driver as a start.

1st Sep 2017, 3:56 am	#7
Terry_VK5TM Nonode Join Date: Oct 2010 Location: Tintinara, South Australia, Australia Posts: 2,340	Re: HELP no display on a FT757 I have just bought Ok, had a dig through my notes. The possible dud transistor on the display board is Q01 (2SC496y). It generates (or is supposed to generate -8v (minus 8V). A replacement for the display driver was available from Rudi, DB6RK. Not sure if he still has them, I got mine a couple of years ago. His email address is on QRZ. Terry