GP340 Bench Testing.

[blacksnake]

Hi Guys,

Total nubee on forum, and know nowt about two-way radio comms, hoping any of you experienced and knowledgeable folks can help...

We use the Motorola GP340 series handsets in work on a daily basis. At some time or other these sets have developed faults, mostly of an intermittent nature. For example: One particular set was fine when carried or clipped to a breast pocket on jacket, but when clipped to waistband it would continuously power on and off when walking? Other sets have just powered off during use even though fully charged requiring user to set power switch to off then back on again?

When a faulty set is reported it's returned to the supplier for bench/vibration testing. Recently, a set (GP340) stopped receiving during use, which resulted in an accident due to loss of comms. Thankfully damage was only to property and not persons. Both the handsets being used where returned for fault testing, and both came back as "No Fault Found."

Could anyone tell me how reliable bench testing is when looking for an intermittent fault. The supplier conducted the tests, and returned the sets within two days. My concern is a repeat incident if the set fails again, last time it was sheer luck that nobody was hurt, we may not be so lucky next time.

Thanks in advance,

Chris.

[bw18]

Hi Chris and welcome.

A few questions... What colour are the rubber seals on the back of the radio where the battery contacts are? Are you using genuine Motorola batteries?

There was a problem with the GP's with orange rubber seals which meant the battery became loose and as a result this caused the exact problem you are reporting. If you are not using genuine Motorola batteries this can also cause an issue as the fit is not as tight as it should be. Even though none genuine batteries are cheaper it is wise to spend more and buy the 'real deal'.

I am suprised your dealer has not found a fault, or identified battery issues. I would be extremely angry if I had sent radios for repair which came back 'fault free' to then subsequently go on to cause an accident... Totally unacceptable in my opinion.

Each dealer who is Motorola authorised should have engineers and the equipment to diagnose every problem going. The GP series is not a new series and there are several common faults known on earlier batch's. I would seriously consider a second opinion from another dealer and see what they say. I have a feeling it is probably the battery contacts that are causing this issue rather than an internal hardware failure!

Ben

[blacksnake]

Thanks for the reply Ben.

They do indeed have orange rubber seals. The batteries we use are genuine Motorola, but of two different types. I dont have the specs to hand but one is a little larger than the other. It's also possible (on some sets) to get them to cycle power on/off simply by squeezing the set and battery.

One more question, if I may...

I have the 'Incident Reports' for both sets and there appears to be discrepancies in a language I don't understand... ... Could you decipher it for me?

Radio #1

Specifications:
TX POWER: 4.3 WATTS
FREQUENCY: -50 CYCLES PER SEC.

RX AUDIO: FULL AND CLEAR
FREQUENCY: -100 CYCLES PER SEC.

Radio #2

Specifications:
TX POWER: 4.5 WATTS
FREQUENCY: +100 CYCLES PER SEC.

RX AUDIO: FULL AND CLEAR
FREQUENCY: +120 CYCLES PER SEC.

The differences in the +/- cycles per sec. between the two sets, does that seem right to you?

I did say I knew nowt! 
Cheers,

Chris.

[bw18]

Sadly I am not an engineer and wouldn't know if these cycles were good or bad!

I would however be confident in saying that the contacts are the issue! A temporary solution (which I did myself for a short time) is wrapping the radio to the battery as tight as possible with good old gaffa tape. This should keep the contacts nice and tight!

I sent my faulty radios to my dealer who did whatever he had to do and they came back perfect (without the gaffa tape lol).

Your batteries are probably lith-ion (the thin ones) and nickel-metal hydride (the fat ones). Lith-ion generally have a higher capacity and can operate for longer durations before needing a charge. Also they are lighter and thinner.

I would get them to another dealer and see what they say. Some dealers will diagnose the problem for free and then charge you for repairs... However, some will charge you just to put a multimeter to the pins!

Someone else on the forum might be able to tell you what the cycles mean and whether they are good, bad or indifferent!

Ben

[blacksnake]

Thanks for your time Ben it's appreciated matey...

[emsgeorge]

elastic band time. Nice thick one. Should sort the issue on a temp basis.

As Ben says, orange seal around contacts = this exact reported issue. Was a board swap I believe, although this is a good 5 years ago, and im not sure what motorola would do with them now, as its too old for warranty.

Black seal is current one.

[bw18]

I think blue onwards you are pretty safe... I did'nt even know they had moved on to black!

Elastic band sounds like a better idea than my rather drastic gaffa tape solution