HR-2510 Troubles

[Quickstop]

Hello All. The trouble i am having with my President HR-2510 is ,
when it is left off for a couple of days , it will not turn on rite ( let me explain) . back in the early summer when it was very humide up here in Ontario, i had my radio at home ,in the basement cleaning up my mic , antenna and coax , it was nice and cool in the basement , when i went to work on monday it was very humide out , but everything in the trunk of car , got to work opened trunk
and everything was damp , boy was i Pisst. i got it in my truck and wiped it off , went to turn it on and all that worked was the display lite. there was no display , a little bite of white noise that was it , nothing else worked ,opened up case and the circuit board was damp to , i wiped off what i could from the circuit board .and let it sit in the front window of my truck for a while , to let the sun dry it out , about an hour later i turned it on and eveything work fine ,, now it is about about 5 months later and it is doing the same thing just more often ,after sitting for a couple of day's you turn it on and just the display lite comes on, you have to turn the radio off and on about 10 times , and then the display will come on and the radio is fine for the rest of the nite, turn it on the next day , it turns rite on no problem, it seems like something gets stuck after sitting a couple of days, My question is ? , is there a mechanical relay in the circuit that could be sticking, if not, any ideas what it might be ? (Sorry for the big story , i just wanted to explain it from the start.)
Thanks for listening , i hope someone can help.

 

[paws264]

I think that your problem is that IC-107, it is mounted on the side of the chassis. It is the 8-9volt regulator that supplys voltage for the radio, the display backlight is run from the 12 volt supply.

I might be wrong (had the same indications) but either the conection from the switch is shakey or the part is intermittent.

.

 

[nvcowboy25]

hum

wow not to steal your post but i have a rci2950dx that does kinda the same thing some times when you trun it on the screen well be blank lights up and has nosie but the lcd numbers and stuff on the diesplay well not be there have to trun it back off and back on agin to get it all to be right

 

[ButtFuzz]

Quick N Dirty Fix

Quick n' Dirty fix:

Turn it on.

Never turn it off

 

[bob85]

i have come across a similar problem with the display not working on the lincolns which turned out to be the blue resonator on the pll board either dry jointed or faulty, i even had a guy bring one for repair that had no resonator, it had been snapped off and the guy swore nobody had opened the radio since it stopped working and could give no explanation why there was a component missing from the display circuit.

 

[paws264]

i have come across a similar problem with the display not working on the lincolns which turned out to be the blue resonator on the pll board either dry jointed or faulty, i even had a guy bring one for repair that had no resonator, it had been snapped off and the guy swore nobody had opened the radio since it stopped working and could give no explanation why there was a component missing from the display circuit.

Hey Bob, in "American", what is a 'resonator', a resistor or what?

.

 

[bob85]

resonators come in different packages, some look like pollycaps in an oblong shaped case, the ones in lincolns look like a dipped mica cap or a ceramic filter with two legs, they have a frequency written on them instead of a capacitance value, i think it acts as the clock oscillator for the display or display driver

 

[paws264]

.

Ok, I would be so lost communicating technically with you guys. We call those things crystals (X-tals) and, like you said they are cut to "shake" (oscillate) at a specific frequency.

.

 

[nomadradio]

If the computer isn't running, the clock resonator is a possibility. It's made from man-made ceramic, like the 3-legged IF filters found in the AM IF section of most CB radios. Since they don't have any quartz in them, the industry refers to them as "resonators", rather than "crystals". They are cheaper than a crystal, take more drive, and the frequency will be far less accurate than from a quartz crystal.

A computer that requires accurate, stable timing from the clock's frequency will use a crystal, rather than one of these.

You wouldn't want to use one to set your channel frequency, but the CPU's clock frequency isn't so critical. Doesn't matter if the frequency drifts a half-percent or so. It's the little blue epoxy-dipped one at the upper left.

The 78M05CV 3-terminal 5-Volt regulator chip is the one at the top of the pic, and should have 13.8 Volts DC (or whatever your power supply is set to) on the left leg, and 5 Volts DC on the right leg. The center one is ground. Doesn't fail often, but will shut down the computer if it does.

No good way to check the resonator with just a meter. A 'scope will show about 4 Volts P-P of 3 MHz RF on one leg, about half that on the other, if it's running. Just don't remember which leg is which.

Fixing a stopped computer without a 'scope is a crap shoot. It's a tool that would settle those questions in a few minutes, and help separate a failure of the CPU from a failure in the driver chip that feeds only the LCD. Since this is not a "common" failure, the fix won't be, either.

Things that go bad frequently like audio chips and finals can be figured out with a meter and good advice, sometimes. Getting that lucky with a surly computer chip is not so likely.

73

 

[Rogerbird1]

Something ellse to look at...

If you look at the pic above, Check to see if the Regulator glue is the tanish yellow or brown or black.

If it is Brown or black(usually brittle, instead of soft), it should be carefully removed and the PCB should be cleaned with Alcohol, then inspected for trace damage. The 'Glue' has been known to become corrosive to circuit traces and in some cases (possibly high humidity) conductive. Also check the 'glue' used to secure the 'Blue Resonator' and the 2 large Electrolytics (one is the MEMORY cap for the Micro the other is the Power filter for the Micro).

Unless your radio is in a high vibration environment you can safely remove it without much consequence, but if you need or want to resecure the components, you can use Hotmelt or RTV silicone.

The Glue is applied per a Mil Spec for Components of a specific size and lead spacing, as used in the ANSI Soldering Standards. In the case of the 'Resonator' just to keep it from breaking loose.

I would pay careful attentention to the solder pass throughs near above & below the 8v regulator, Those are prone to corrosion/shorting.

Roger

 

[The Defpom]

I have had to repair about a dozen or so HR2510 / HR2600 in the past year or so, I would certainly start by removing the CPU PCB and resoldering the CPU pins, I have found them to be troublesome sometimes, especially if it has been replaced with a "chipswitch", or had the 26MHz mod done to it.

If you are unsure about the adhesive on the voltage regulators I have found that once the adhesive starts to conduct it causes noise on your transmitted audio, which is more noticable on SSB, if you can hear white noise or very quiet crackling on your TX audio lift the voltage regulators and replace the adhesive.

 

[Quickstop]

I am going to try one step at a time, to start where do you buy
the Hotmelt or RTV silicone ? , is it a common item or do i need to go to an electronic shop. and in the picture where is the CPU PCB.and yes this radio is subject to lots of vibration, it is bungie straped to the dash of my truck {Transport}. and it has to be taken out every nite when i am done , i drive company truck and never get the same one twice., i have been taking it in and out for 7 years now, the radio is 12 yrs old . whick glue do i use on the voltage regulator the Hotmelt or RTV silicone and then on the Blue resonator

I am very Thankful for all the advice you guy's have given me
Thank You

 

[Rogerbird1]

Supplies

Hotmelt kit can be found at most hardware stores or Home Depot types. Even WalMart. Usually comes with a HotMelt glue gun and some Glue Sticks.

RTV silicone can be found in the same places.
Neither is typically used for electronics.

Roger