Hello,

 

I have a 2008 Focus mk 2.5 with an intermittent fault on the instrument cluster. All lights go off and gauges go to zero, this can be reset by restarting the car.

 

I have taken the cluster out, disassembled and repaired the cracked solder joints on the back of the PCB, where the connector goes.

 

However the fault still exists.

 

I highly suspect it's a poor connection somewhere on or around the cluster. If I hit the top of the dash, above the cluster, with my fist, the fault happens or clears itself.

 

My question is..... where are the solder weak points on the PCB, excluding the connector pins ?

 

Thanking you in advance.

 

Chris

I know it's not the question you asked and you have obviously tried to fix this so all I can suggest is looking at this and seeing if they can help?:

https://www.sinspeed.co.uk/ford-focus-instrument-cluster-repairs/

1 hour ago, chrisxbates said:

where are the solder weak points on the PCB, excluding the connector pins ?

The whole of the instrument cluster was originally soldered using "lead free" solder so every joint is a potential week point.

To do the job properly each pin must be desoldered and the lead free solder removed. Then a flux used and each joint reflowed using real 60/40 lead tin solder. It takes time if you are to get a good reliable electrical connection.

@rd457 can advise and help.

3 hours ago, chrisxbates said:

I have a 2008 Focus mk 2.5 with an intermittent fault on the instrument cluster. All lights go off and gauges go to zero, this can be reset by restarting the car.

I have taken the cluster out, disassembled and repaired the cracked solder joints on the back of the PCB, where the connector goes.

However the fault still exists.

I highly suspect it's a poor connection somewhere on or around the cluster. If I hit the top of the dash, above the cluster, with my fist, the fault happens or clears itself.

My question is..... where are the solder weak points on the PCB, excluding the connector pins ?

Hmm. I provide a repair service through ebay, I've repaired over 230 units, the majority of which are identical to yours, and the only thing I ever have to repair on them, besides the odd dead LCD or failed DIY repair, is cracked connector joints. While Ford no doubt used lead-free solder for everything, the connector joints are the only ones I've ever seen cracked, which is probably because they are the only ones that get subjected to any stress. So essentially that's the only relevant weak point that I know of.

It sounds like power is being lost. If bashing the dash still makes a difference after your repair then I'd concur that it seems that something is still wrong with the cluster, or the plug. Without meaning to offend, if could just be that you've done a bad job of the repair somehow, or you could have knocked something creating a damaged connection, or it could be a tiny bit of grime somewhere on the board creating a short though that maybe doesn't correlate with the shock factor. Have you tried a drag test with the plug?

13 hours ago, chrisxbates said:

I have taken the cluster out, disassembled and repaired the cracked solder joints on the back of the PCB, where the connector goes.

 

Have you just reflowed the original solder?

6 minutes ago, DaveT70 said:

Have you just reflowed the original solder?

I have not removed the old solder. I have reheated the joints and added a little 60/40 old solder to it. I did work for 25 years on electronic circuits and can assure you there is not wrong with the joints I have remade. 

9 hours ago, rd457 said:

Hmm. I provide a repair service through ebay, I've repaired over 230 units, the majority of which are identical to yours, and the only thing I ever have to repair on them, besides the odd dead LCD or failed DIY repair, is cracked connector joints. While Ford no doubt used lead-free solder for everything, the connector joints are the only ones I've ever seen cracked, which is probably because they are the only ones that get subjected to any stress. So essentially that's the only relevant weak point that I know of.

It sounds like power is being lost. If bashing the dash still makes a difference after your repair then I'd concur that it seems that something is still wrong with the cluster, or the plug. Without meaning to offend, if could just be that you've done a bad job of the repair somehow, or you could have knocked something creating a damaged connection, or it could be a tiny bit of grime somewhere on the board creating a short though that maybe doesn't correlate with the shock factor. Have you tried a drag test with the plug?

Thanks 

11 minutes ago, DaveT70 said:

Have you just reflowed the original solder?

I have not removed the old solder. I have reheated the joints and added a little 60/40 old solder to it. I did work for 25 years on electronic circuits and can assure you there is not wrong with the joints I have remade. 

7 minutes ago, chrisxbates said:

I did work for 25 years on electronic circuits and can assure you there is not wrong with the joints I have remade. 

If the cluster still isn't working then the repair was unsuccessful.

@rd457 has done hundreds of these, he knows what he's on about

7 minutes ago, chrisxbates said:

.. there is not wrong with the joints I have remade. 

At the moment, you have a giant paper weight on your hands. For the sake of not very much at all, you could have it back to working order. I know which I'd do...

2 hours ago, chrisxbates said:

I did work for 25 years on electronic circuits and can assure you there is not wrong with the joints I have remade

I can beat that - I worked on electronics for 45 years .

Nothwithstanding what you've said I'd recommend re-doing the repair, removing all the old solder using solder wick (or a desoldering tool if you have one*), and resoldering with 60/40 solder.

* you probably already know this but if using a piston-type desoldering pump you need to be very careful - the recoil can cause damage, even lifting the track.

16 hours ago, chrisxbates said:

All lights go off and gauges go to zero, this can be reset by restarting the car.

 

16 hours ago, chrisxbates said:

If I hit the top of the dash, above the cluster, with my fist, the fault happens or clears itself.

Have you tried the CAN bus resistance test: 60 ohms between the lines with ign off, most easily measured at the DLC (diagnostic socket)? 120ohm typically indicates a broken bus, as each end (IC & PCM) has a 120 ohm terminating resistor.

But from the fault description, it sounds more like the power supply to the cluster. Wiggle the wires into the connector, and have a good look for corroded tracks on the cluster.

Also, much of what is said about lead free solder is simply wrong. Many Billions of good solder joints made with lead free solder prove that. The real weakness arises when lead free and leaded solder and components are mixed. This allows the formation of lead-tin alloys that have very variable alloy percentages, and can create weak layers in the joints. Equipment made around the time of the change-over to lead free did often suffer from this, due to poor control over the parts and soldering systems, mixing the two types. If you have lead free equipment, always use lead free solder and iron tip for repairs. For old equipment, if it is leaded, use 60/40. If uncertain, clean the joint, re-make with lead free, and if critical, clean it again and re-make it to minimise any lead remaining.

5 hours ago, Tdci-Peter said:

 

Have you tried the CAN bus resistance test: 60 ohms between the lines with ign off, most easily measured at the DLC (diagnostic socket)? 120ohm typically indicates a broken bus, as each end (IC & PCM) has a 120 ohm terminating resistor.

But from the fault description, it sounds more like the power supply to the cluster. Wiggle the wires into the connector, and have a good look for corroded tracks on the cluster.

Also, much of what is said about lead free solder is simply wrong. Many Billions of good solder joints made with lead free solder prove that. The real weakness arises when lead free and leaded solder and components are mixed. This allows the formation of lead-tin alloys that have very variable alloy percentages, and can create weak layers in the joints. Equipment made around the time of the change-over to lead free did often suffer from this, due to poor control over the parts and soldering systems, mixing the two types. If you have lead free equipment, always use lead free solder and iron tip for repairs. For old equipment, if it is leaded, use 60/40. If uncertain, clean the joint, re-make with lead free, and if critical, clean it again and re-make it to minimise any lead remaining.

Thanks. No I have not done a can resistance test. If the fault peruses I may, but need to do a little more research first.  

An update.

I have taken the cluster out for a second time. Inspected the circuit board for cracked joints especially around the larger components, these in my experience are the ones prone to mechanical stress and hence failure. I did not see any cracked joints. I did reheat a several joints around the larger components and those associated with the two voltage regulators. 

Also removed the old solder from the connector and remade the joints. 

Put it all back together, all okay. At least I have not made things worse.

It passes the dash thump test. 

Fingers crossed.

5 hours ago, mjt said:

I can beat that - I worked on electronics for 45 years .

Nothwithstanding what you've said I'd recommend re-doing the repair, removing all the old solder using solder wick (or a desoldering tool if you have one*), and resoldering with 60/40 solder.

* you probably already know this but if using a piston-type desoldering pump you need to be very careful - the recoil can cause damage, even lifting the track.

Thanks

An update.....

After re-soldering the pins on the cluster PCB yesterday, the fault reappeared today.

During re-installation yesterday, with the cluster plugged in and energised, I waggled the connector, I could no replicate the fault. Also tried flexing the cluster, again no fault. 

I'm doubting it's poor PCB connections. 

I'm a little disappointed to say the least.

 

 

 

 

I had my son’s 2008 ST professionally repaired/reconditioned 3 yrs ago for £100 as they could test it before returning it to us.

They did replace a capacitor on the other end of the PCB at the same time.

He did drive it 300 miles back from holiday by slapping the dash/cluster before having it repaired.

P.S.  dtcs through the obd could help diagnosis