EQ5 Handset Repair

[StarryBob]

Does anyone know if they can be repaired? A friend of mine has just had one go dead. It was working fine then he caught the lead and pulled it out of the mount, plugged it back in and it's not even lighting up. He has tried my handset which works ok so it's not the mount and he has tried power directly to the handset but it's still dead. The lead has also been checked and that's ok too. He was hoping there might be a way to repair it as he has little money since losing his job unfortunately.

[badgerchap]

I fried mine the other day with too much voltage - it's irrepairable as far as my skills go.

Yours doesn't sound like the same problem though - from the sounds of things, on of the 2 wires that connects the power input to the circuit board has come loose. If you're not even getting a light in the middle, then this, or something fairly similar, is probably the issue. The wires are not very well secured / soldered, and can break fairly easily (I know - I broke mine just taking the back off it!)

Open it up and have a look is the best bet - unless you want to try getting a replacement from the supplier. They'll tell you where to put it if you've had the back off!

[StarryBob]

It's well out of guarantee, I took the back off and had a look with a multimeter and it seems to be getting 12 volts in and it changes to 5 volts a couple of internal connections later. The rest is beyond my limited ability. There are no burn marks or broken circuits so it must be a component fault, I could probably have repaired it had it been a blown circuit board I think.

[Geesus]

As Badgerchap says - if it looks like there's no power getting to anything then check those wires first... Do you/he have a multimeter that you can use to check it out?

I know it can be worth asking the supplier for a replacement - I know that when I had a kiteboarding accident that ended with my £80 kite control bar being cut off by a paramedic the supplier was more than happy to replace it if I paid the postage fees... would definately be worth asking before you take the back off!

Failing this it's fairly easy to diagnose electronics problems with a multimeter if you know what you're looking at... if it's a fried fuse/resistor/diode/capacitor etc. that should be fairly easy to spot and replace if you're careful with a soldering iron, however microcontrollers can be much harder to diagnose and replace as you've got no blumming clue what the programs they're running are doing unless you have the correct software and a good knowledge of the coding language used!

Hope some of this helps!

(I've studied electronics for the past 5 years and i'd still be scared of messing about with that kind of circuitry!)

Ginger

[StarryBob]

I have just put it away for the night, I'll take another look tomorrow. I have check for live and there seems to be plenty point around the pcb where it gets 5v, I will check the negative/earth side tomorrow and see how that looks. All the components are very small and the main chip has many connections. I think without a schematic it will be a bin job.

[badgerchap]

Oh dear - if it's getting 12 volts that could be the problem. It's rated at 6v - that's how I fried mine! It's definitely EQ5 not HEQ5? I only ask cos the latter is 12v, but the former is 6v...

[Geesus]

12v in doesn't necessarily mean the circuit will be getting 12v... I read your blog (badger) and you've definately got more experience with this circuit than me, but it IS possible that the input voltage would be put through a potential divider, (simple circuit consisting of two resistors in series... if the resistors are the same value then the point in the middle will be input voltage / 2). Depends what power source was cheapest to manufacture etc...

Am I right that it's run off a DC battery rather than AC mains/transformer etc., as this eliminates the possibility of a diode/capacitor having blown in an AC -> DC circuit!

Just a thought...

Ginger

[StarryBob]

It definitely has 12v going in as does mine, I checked that first and they're both EQ5s. The handset power connector for upgrading the handset is 12v too. In the handset there seems to be a voltage converter that changes it to 5v and this is quite close to the connectors.

[badgerchap]

First components are a bunch of transistors in parallel with a bunch of resistors. To be hones Geesus, I've not actually examined the circuitry properly. Electronics is a part of physics I learn because I have to, but I'm not very talented lol. I like my physics astronomical! What I am fairly certain of though is that if any power is getting to the unit at all, the normally green frontlight goes red, indicating a component failure.

The unit runs either on battery or DC PSU.

Sorry then Bob, if yours takes 12v, then it's a different handset to mine! Are you using batteries?

I've just had a brainwave - is this the goto handset by any chance? If so, I'm really sorry but I've been completely wasting your time - my handset is just the Dual Axis motor, but I've a feeling you have the goto, in which case I have no experience whatsoever! Sorry!

[StarryBob]

Yeah it is the goto, you had me concerned for a moment lol. That would explain why yours is 6v alright

[badgerchap]

Ah well - back to the drawing board then! TBH I can see why he's not up for replacing it then, theyre a tad more pricey than the Dual Axis kits!

[StarryBob]

I appreciate you trying help, I thought for a minute we were onto something. I guess there are no obvious repairs but if anyone does know of someone who can repair electronics please let me know.

[Geesus]

You say there's one big chip in the circuit... does it have any writing on the back? If so, identifying the chip and resetting it could help if there's power getting where it's supposed to?

Just a thought...

Ginger

[StarryBob]

I take some pics, that might help