2995dx issue

[zinger827]

Radio Make and Model: RCI 2995dx
PCB Number: 695014B
PLL Number:
Test gear available: vom meter
Symptoms: Display blacks out when transmit? Also makes a weird noise once display goes out?

What is working: Everything else works normal.

What has been tried: I unplugged power to amp and when power turned up w/driver and final it keys about 1/2 watt and stays on a few seconds before display goes out? When power turned up to around 2 watts it instantly blacks out.

Did it suddenly happen ?: bought this way as not transmitting but what I said for problem is the actual problem as it does transmit?
Anything else that may be of help?:

[KC7NOA]

If not bought new ... sounds like Rf getting into the displays Vcc .... supply voltage ....

There is an amp on that thing right? Disable the amp and see if it still does it.

[zinger827]

If not bought new ... sounds like Rf getting into the displays Vcc .... supply voltage ....

There is an amp on that thing right? Disable the amp and see if it still does it.

Hi I did test it w/amp disabled still does it. I did put a external PS to the mainboard and it worked perfect? I undo the ext. PS and back to square one. Then I put in the 754 voltage regulator and the smaller transistor on the PS board and got back my voltage to main board but when key up it blacks out still? So I am guessing the 3771 transistors possiby? I am going to change them in the morning and see what happens. Will update tomorrow. Thanks.

[zinger827]

I fixed the problem had bad voltage regulators and power transistors for the power supply. I replaced them and back to talking. Thanks.

[KC7NOA]

Good deal ... hope radio was cheap! !!

[zinger827]

Good deal ... hope radio was cheap! !!

Radio was bought cheap $260 w/fan kit shipped its about 3 years old just before the switching PS. Fix costed me $1.50 for 2-3771 transistors and the 2 regulators I had from a stripped 2990 so I dont have to much into it. Took a chance on it and did alright thankfully.