XTS2500 LCD goes crazy on Tx

[Eaton]

Hi folks!
I've swapped a case on my XTS2500 VHF. The new one didn't have an LCD installed so I ordered one from China (yes, I must admit it).
Everything works great when radio is in Rx mode, but as soon as I press the PTT button the LCD goes like this:

Has anyone seen something like this before? Why does it happen and what is to be done to stop it? It really pisses me off! (however not having an LCD at all is much worse)

Not long ago I found one online store which offered LCDs for XTS radios. What I noticed there is that they have 2 different types of LCDs for sale - one for the VHF radios, another - for UHF and 700/800 ones. Could it be so the display is wrong for my frequency band? I doubt it because I worked on the radio in question with another case attached which was pulled of the UHF radio and the LCD worked like a charm on both VHF and UHF models.

So, maybe it is a lack of RF shielding?

Oh, yes, the radio is a BN model and runs R16.00.01 Host/DSP firmware, if this helps

Any help would be appreciated!

 

[MTS2000DES]

Using the wrong version of the LCD module will produce that effect, so will a loose flex cable. IIRC the latest version of the display is a version "C03" and isn't band specific.

What version did you install in your radio?

 

[Alpha]

I think the latest is C04. I had a VHF radio that did that a lot previously, sometimes it would garble or flip upside down! VHF seems to most prone to having problems.

Some of the earlier displays were actually band-specific (!) I don't know what was peculiar about them, maybe the bypass capacitor frequency was band-specific, I'm not sure, but I have seen a table that actually lists the bands and the matching suffixes. The latest revision one seems to be band-agnostic. Anyway with my situation I had a C01 or C02 that was going nuts in a VHF (can't remember exactly) and an 800 radio, so swapping the two fixed the problem, and the older display had no issues on the other band radio.

 

[Eaton]

Ok, thanks for the suggestions!
Where do I look the version of the LCD up?

I will try using this LCD on a UHF radio, now I wonder if it will go on flashing this way on a UHF

 

[Mars]

It's got to be a capacitor or inductor (or combo of the two) value which bleeds RF off to ground on the LCD PCB. Would be neat to compare the various boards. I had one that did the same thing. Another reason I'm not fond of the 2500. There's very little shielding in that radio. The keypad/UCM is wide open, too. Nothing but plastic/rubber between the front of the radio and the keypad/UCM board. Only one side of the UCM is shielded, as the keypad side must remain uncovered.

 

[Alpha]

The version is stamped on the back of the flex cable it will say "C04" or the like. Try swapping, them you have nothing to lose... Either it will help, stay the same or get worse

 

[Number 6]

A "real" LCD will have the version label on the flex at the connector end of the cable. The label will be facing you when you look inside the housing.

C04 is the latest version and works on any band - that's what you want to use and I've installed many without a problem. Of course, they were Motorola parts. Unfortunately, I sold my last one to a member of this site or I would send one for you to try.

What you are experiencing is likely an RF problem that others have experienced as well and have discussed on this site and others if you want more info. There could be other causes than the LCD itself, since, as the other mods have said, the radio is light on shielding. I've even run into the situation where a brand new housing would work on one radio but have problems on another.

 

[Eaton]

Ok, here's the update.
I've cracked open both radios. The LCD from the UHF unit (the left one) appeared to be C04, the one from the VHF left unidentified (see the pic attached).

The "whacky" LCD proved to work flawlessly on the UHF radio so I just swapped the LCDs (swapping cases is unappropriate for me since one is M2 and another is M3)

it really shocks me how XTS1500/2500 radios are cheaply-built...

Again, thanks to everyone and all this forum for being so helpful and responsive!

 

[escomm]

The whacky LCD is then by process of elimination a C02 display, which would be for UHF. C01 for VHF, C03 for 800. The C04 was then band agnostic. And was then replaced by the 001 display. So the current part number for an LCD that will work in any band radio is 72009264001.

Btw, pretty sure the C01-C03 did the same funky stuff when used in the wrong band XTS5000

 

[Alpha]

Also another FYI is you might find the P/N inked in tiny print on the flex somewhere else - the whole P/N not just the suffix, but it will end in C01-4, FWIW. Probably academic by now, but that may be another way to determine part number...

 

[SD70MAC]

I had the same problem with an XTS5000 VHF and the C04 display will fix the issue. You may want to get you a housing tool also because it is easy to damage.