Need help for broken Transporter

[Sokrates]

Thank you so much for this fantastic thread! My Transporter was sleeping for 2 years and came back to life in an instant after replacing the internal PSU. Love it!

[JoeMuc2009]

Cool, it's the best reward to find that others can use the info presented. Happy listening!

[05mattjax]

Own a couple of Transporters bought recently. Don’t have these issues but decided to buy a few of these just in case.

Great thread to stumble across.

I suspect some believe if the screen has died it’s an expensive screen replacement and not just a £10 circuit board.

[michel]

another one saved

Replaced both 680µF 10 V caps and the Transporter is up and running again. Cost was 60 Eurocent!

[andrewhess]

I've had mine (Modwright Transporter) for over ten years now. Would it make sense to prophylactically replace those caps? If so, would I keep the same values or upgrade them?

[JoeMuc2009]

I've had mine (Modwright Transporter) for over ten years now. Would it make sense to prophylactically replace those caps? If so, would I keep the same values or upgrade them?

Hi Andrew,

certainly makes sense to replace them. The voltage rating should be at least 10V but there is no harm done if you choose one that would tolerate 16 or even 25V. Eventually, 5V is what they constantly need to handle, but a bit more margin would not hurt. Higher voltage ratings mean bigger size though.
The capacitors are connected in parallel so their combined capacity adds up to 1360µF. A discharged electrolytic capacitor has a low resistance at first which causes some load on the other components. The higher the capacity, the longer this low resistance stands (as charging it up takes longer). So don't use crazy values like 10000µF even though these are available. The circuit is just not designed for it.
There's a third value to keep in mind which is the temperature rating. As far as I know there is 85°C and 105°C, that's the maximum allowable ambient temperatures they can stand. The higher the safer, but again, higher tolerance might end in a larger size.
Be aware that you need to mind the correct polarity of the capacitors. Putting them in reverse might blow them up, or at least cause them to fail quickly.
Choosing two new 680µF, or a single one having 10V/1500µF is reasonable. I would definitely not recommend to go beyond 2200µF, it might damage other parts of the power supply board. If you can, let the new capacitors stand further away from the board as there is a diode near their home position that gets very hot during operation, and heat has them age quicker. Here is an example of a ModWright Transporter that I did a maintenance run on recently. Not pretty but efficient:





This power supply will last way longer than the original setup, I'm sure.

I was actually a bit disappointed by the mess they made when they modified the Transporter. The display flat flex connector on the front panel board was falling apart because it was not handled properly, and the connector for one of the main power rails (set of two purple wires between the toroid and the MW board) was burning up internally due to bad contact. The way the 5V power supply is pushed aside to make room for the overkill toroidal transformer did not appear very safe. Wiring between the MW board and the analog part of the Transporter mainboard was a mess, too. But anyway, after fixing it all, the owner confirmed the sound is positively worlds apart from the stock Transporter audio quality. So apparently it's worth it.

Good success on your repair!

Cheers,
Joe

[andrewhess]

Sounds good. I'll put it on my list. Thanks!

What's the value of the cap on the left? So, just those three caps, yes?

[JoeMuc2009]

Right. the big cap on the left is working on the primary side and is rated 22uF 400V (uF is for microfarads)


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[slartibartfast]

Hello, I have a broken SB3 and I am trying to contact you for repair, but I cannot send PM, as I am a new user maybe I dont have enough privileges. I have also sent you an email to the address you mention in your blog.

Thank you in advance!

If you make a few more posts PMs will become available. Not sure how many but at least 3 and less than 5.

Sent from my Pixel 3a using Tapatalk

[spt87a]

Been reading up on the Transporter power supply topic with great interest - thanks to everyone for all the good info over the last few years.

My own Transporter throws a lot of noise which impacts AM radio throughout my house. I moved last fall and didn't notice this occurring at my last place so I believe the Transporter has developed this problem recently. Wondering if this is an early sign of caps failing on the power supply. Has anyone noticed this or can anyone comment if their Transporter causes this same interference? I did have issues with mine getting running after the move and ended up doing a full reset of it (xilinx; try regular reset first which didn't help). It didn't want to connect to WIFI even though it was the same WIFI router/name, etc. as before the move. It has been ok since other than the AM noise.

In my case - I have the Transporter in a rack below a Denon tuner. With the Transporter plugged into power there is noise across the entire AM band. Unplug the Transporter and it goes away. I have other nearby devices - XBOX One, cable DVR box, TV, etc. and no noise from them. With the Transporter plugged in again, I then try my tube based 1950's/60's table radio in the kitchen and same AM noise which goes away with Transporter unplugged. Pretty sure the noise is going thru the power lines as I haven't noticed the problem with battery powered radios.

If no one has info on this I'll likely just try to recap the power supply and see if it fixes it.

[JoeMuc2009]

Been reading up on the Transporter power supply topic with great interest - thanks to everyone for all the good info over the last few years.

My own Transporter throws a lot of noise which impacts AM radio throughout my house. I moved last fall and didn't notice this occurring at my last place so I believe the Transporter has developed this problem recently. Wondering if this is an early sign of caps failing on the power supply. Has anyone noticed this or can anyone comment if their Transporter causes this same interference? I did have issues with mine getting running after the move and ended up doing a full reset of it (xilinx; try regular reset first which didn't help). It didn't want to connect to WIFI even though it was the same WIFI router/name, etc. as before the move. It has been ok since other than the AM noise.

In my case - I have the Transporter in a rack below a Denon tuner. With the Transporter plugged into power there is noise across the entire AM band. Unplug the Transporter and it goes away. I have other nearby devices - XBOX One, cable DVR box, TV, etc. and no noise from them. With the Transporter plugged in again, I then try my tube based 1950's/60's table radio in the kitchen and same AM noise which goes away with Transporter unplugged. Pretty sure the noise is going thru the power lines as I haven't noticed the problem with battery powered radios.

If no one has info on this I'll likely just try to recap the power supply and see if it fixes it.

I guess the power supply could be part of the issue but if your Transporter is still working as it should, so is the power supply. Dying capacitors might have some components swing, but in my opinion that would not be in the range of radio frequencies. Anyway, what I dislike a bit about the Transporter's hardware design is that the aluminum case is not really properly grounded. The IEC connector earth terminal routes on the PCB to one of the nearby bolts that secure the board. The trace is rather thin, and the connection is at best weedy. Usually one would expect a beefy green/yellow wire that goes from the terminal directly to a solid nut-and-bolt connection in the bottom of the case using shake-proof washers and isolation material. Either that was too expensive or they just didn't know how to do it. So it might be good if you checked how well the connection from the metal case to the earth terminal actually is. With a bit of mechanical skills it would be easy to improve the situation by placing an additional grounding wire. The aluminum case itself is not actually airtight, around the Ethernet and serial IO there is some gap, that's also where the most dust accumulates over the years. But I would not assume that these slim gaps actually let unwanted RF emissions escape. If so, they would also be measurable or even audible in the Transporter's own analog outputs.
Unfortunately I don't have equipment to systematically trace emissions from my Transporter, and no analog tuner in use anymore. An oscilloscope loop probe would be ideal to find out where exactly the emissions are coming from. Do you see any chance to get a hold of something like this?

[Redrum]

Been reading up on the Transporter power supply topic with great interest - thanks to everyone for all the good info over the last few years.

My own Transporter throws a lot of noise which impacts AM radio throughout my house. I moved last fall and didn't notice this occurring at my last place so I believe the Transporter has developed this problem recently.

In my case - I have the Transporter in a rack below a Denon tuner. With the Transporter plugged into power there is noise across the entire AM band. Unplug the Transporter and it goes away. I have other nearby devices - XBOX One, cable DVR box, TV, etc. and no noise from them. With the Transporter plugged in again, I then try my tube based 1950's/60's table radio in the kitchen and same AM noise which goes away with Transporter unplugged. Pretty sure the noise is going thru the power lines as I haven't noticed the problem with battery powered radios.

.

If I might jump in with a couple things to try...

I have this problem with a touch, in the same rack with some arcam gear, including a tuner, and always assumed it was the power supply. I never traced it down, just stream the AM station I am interested in. But, I know what you are experiencing.

It still could be EMI/RFI, but it seems like you think that the transporter is imparting noise on your power lines, and it didn't happen at your old place, I assume the gear is positioned similarly in the same rack. It also seems that it isn't happening with all equipment on the same outlet/circuit because your kitchen radio has the same problem. Do I have this correct so far?

Two things:

- see if your kitchen outlet is on the same circuit as where your kit is plugged into.
- try an outlet that is on the other "phase" of the house power. Don't know where you are located, but here in the US our 240/120 comes in with 2 hots a neutral and a ground. two "phases" 120 is derived from HotA and Neutral, and HotB and Neutral. In our circuit box, HotA is on the left (odd number breakers), HotB is on the right (even number breakers). If we need 240, the connection in the box is HotA to HotB (phase to phase).

So, you can look at your box, find a circuit that is on the opposite side from your kit's outlet and run an extension chord from a nearby outlet on the other phase to your transporter to test.

I suggest this because those "power line ethernet" adaptors work by modulating the signal on the power lines. They work best if it's the same circuit, but still may work if it's the same phase. It's highly unlikely that the work phase to phase.

This would at least tell you if the noise is being imparted on the power line, or if its travelling through the air (more insidious )

Jim

<edit - The one thing I forgot to mention. While I am sure that this "just started happening" is possible, I always tend to focus on "what changed", even if it seems unlikely. In your case, it's the house. Just my opinion>

[Mike2]

Does anyone know how to remove the transnav knob on a Transporter?

[JoeMuc2009]

Does anyone know how to remove the transnav knob on a Transporter?

Hi there,

just pull it straight away, it will come off. Or is this about removing the entire knob assembly to make your Transporter an SE model? (why would you want that?)
In that case, you will have to open the Transporter, undo the hex nut that secures the 'Immersion' knob assembly and unplug its 4-pin connector. I think that's all, you might need to flash the SE firmware because some knob functions need to be replaced by other buttons.

Cheers,
Joe