Lacuna charger info needed please!

[mrtrev]

Hi everyone,

I'm new to the forum, just wondered if someone could help me out with a little problem.

I have been given a Lacuna Mk2, the only problem is it doesn't have a charger. From memory I think they are 12v DC @ 300mA, but I'm unsure of the plugs polarity (center positive or center negative?). If anyone has a Lacuna charger could you have a look on the back to see what the specs are please.

Apologies for bringing up such an old model, but I'd like to get it charged up to see if there's any life in the old dog ;) Any advice on this would be greatly appreciated.

Regards,

MrTrev

[mrtrev]

Anyone?

[Detlef]

I assume you have had a good look, with a magnifying glass, on the meter next to the charger input socket. Most equipment has a tiny printed or raised logo showing the polarity.

Unfortunately Lacuna ceased trading so no technical advice from them but there are several firms that supply chargers so you might be able to get info from them.

[mrtrev]

Hi Detlef, thanks for the reply :respect-054:. unfortunately there's nothing at all, although I will double check. I did hope that someone with the charger could look on the back of it to see what its specs were, as output voltage, amperage and polarity are on them 9 times out of 10. And yes as you rightly mentioned Lacuna are no more, which is a shame.

[mrtrev]

I've discovered that this unit needs 12v @ 300mA & the center pin is positive.

Unfortunately I've also discovered that there's a missing component on the circuit board :( looks like a surface mount transistor that feeds power to the battery.

Anyone here familiar with the main circuit board?

[mrtrev]

I'm sorry to go on, but I'm really eager to get this Lacuna MK2 working again. Does anyone have one of these units? I need a part number from one of the transistors. It's about an inch up from the positive battery pin and is directly opposite (almost mirrored) another transistor. You can see the solder pads and where the part is missing. If anyone can fill in the blank for me that would be brill...

55780

[acssim]

I've got a Wolsey Mk2 DTM Terrestrial meter but its PCB seems similar to yours (my PCB is labelled SATMETER 2-6).

The missing transistor on mine is marked "JJ" with "P3" in smaller letters down the left hand side (its "partner" on my PCB is marked "1Ep"). Identical "JJ" devices are fitted on my PCB at the top left near the mini DIN socket and next to pin 1 of the LCD connector.

Hope this information helps.

[acssim]

Futher searching shows the JJ device may be a BAV70T dual diode :

http://www.s-manuals.com/smd/jj

[mrtrev]

Thank you for the information acssim, I really appreciate your input :respect-001: I will investigate this further. If you could take a photo and upload it in this thread that would help too.

[acssim]

You're welcome. I'll try and get a photo of the board done tomorrow, if that's ok.

[acssim]

Here's a photo of my Wolsey DTM Mk2 PCB, as requested.

As you can see there are differences between the components fitted on our boards. Maybe the designer simply used a common PCB for both the Sat and DTT versions, with different components fitted as required?

It looks like someone may possibly have removed 2 large silver capacitors from mine but, as I got my meter second hand too, I don't know its history.

Whatever the reason, my meter seems to works ok and the battery gets charged when a PSU is connected. I don't know what the official charger was but I use a 12v 1amp PSU that seems to work.

Ignore the DIP socket on a wire - that's me playing with the EEPROM to update the stored Freeview transmitter data (I haven't found the PC program to do that yet so am doing it the Nerd's way).

Hope this helps. If you need any more information, just ask.

[mrtrev]

Acssim, you are an absolute legend, thank you for your help. I think you're right about the common board and they are then tailored to suit the application. These are great little meters. I'll keep you posted on the outcome, hopefully my MKII will live again :D

[acssim]

Glad the information was appreciated :D

Have you managed to get the meter up and running again?

[mrtrev]

Not yet, between work and family commitments I don't get much chance to get into my workshop. As soon as I get some free time I'm on it and will let you know. Once again you've saved my bacon on this one :)

[szabby]

]

hi pls help me i cant find how to upgrade my Wolsey Mk2 DTM Terrestrial meter thx